textproduct: Albany

WHAT HAS CHANGED

High temperatures for Sunday have been lowered by a few degrees to account for cooler model solutions due to widespread rain during the daytime. Outside of continuing to monitor potential for a coastal storm late in the forecast period, no significant changes were made to the forecast in this update.

KEY MESSAGES

1) Widespread light to moderate rain remains on track for the area Sunday, with no flood concerns expected.

2) A coastal storm will track near the East Coast late next week, but confidence remains low on whether we will see impacts from this system at this time.

DISCUSSION

KEY MESSAGE 1... After a gorgeous day which will feature a mix of sun and clouds with highs in the 50s/60s, our weather will turn active across eastern New York and western New England to close out the weekend.

To our south, a stalled frontal boundary is located from central Iowa into the southern Ohio River Valley and Carolinas. As southerly flow strengthens tonight with the formation of a surface low across the mid-Mississippi River Valley, this boundary will quickly move north as a warm front into the Mid-Atlantic, aided by a 30-40 kt 925- 850 hPa LLJ. This jet will strengthen moisture transport into the Mid-Atlantic and southern New England, with PWATs climbing to around 1.50-1.75" in these area per the NBM. The combination of this moisture and lift provided by the front and trailing surface low will result in a light to moderate stratiform rain for the region for much of the daytime, with activity expected to wane by evening as the low departs off the coast of Cape Cod. Expected rainfall hasn't deviated much from the previous forecast, with amounts ranging from about half an inch across the western ADKs, to around 0.75-1.5" along and south of the Interstate 90 corridor. Locally higher amounts will be possible across the higher terrain of the Catskills and the Interstate 84 corridor. Daytime temperatures will struggle to hit 60 across the high terrain and areas north of Interstate 90, though low to mid 60s are expected for valley locations south of the Albany metro.

Thinking regarding hydro concerns remains unchanged from the previous AFD. Given the lack of available instability, stratiform nature of the rain and high FFG values, flash flooding is not expected Sunday outside of nuisance ponding of water in low-lying, urban, and poor drainage areas. This rain will actually be beneficial for most, especially across the Mid Hudson Valley, western New England and Mohawk Valley where dry conditions have prevailed with below normal precipitation in the last 1-2 months. River flooding probabilities are also low with HEFS and National Water Model ensembles maintaining river level forecasts below action stage.

High pressure will follow behind the low and a cold front for early next week, which will result in a pleasant, dry start to Fall across the region. There do remain some low chances (10-30%) of rain showers mainly across Ulster and Dutchess counties early Tuesday with a passing surface low across the Ohio River Valley, but most will remain dry. Temperatures each day will range from highs in the 50s (terrain) to 60s (valleys) and lows in the 30s (terrain) to 40s (valleys).

KEY MESSAGE 2... Latest guidance continues to hint at potential for a coastal system to impact the region late in the forecast period. The GFS remains the most aggressive in bringing a strong upper level trough into the Appalachians and Virginia coast, with development into a cutoff low off the Mid-Atlantic coast early Friday. Given high levels of moisture expected to accompany the system, we will continue to monitor its placement and trends in the coming forecasts.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Through 00z Monday...VFR conditions currently prevail across all terminals with high-level clouds continuously streaming into the region ahead of an incoming low pressure system. Throughout the night, high-level ceilings will begin to lower as low-level moisture increases, though remain well within VFR thresholds into the early morning. Light showers are expected to precede the filling in of a stratiform rain shield by between 09-14z. Conditions here will likely remain within low VFR thresholds as low-level dry air will take some time to be overcome. However, by 11-14z, steady light rain will lower ceilings and visibility into MVFR thresholds. Embedded moderate rainfall rates could even take conditions at some sites into IFR thresholds. This looks most likely at POU where the heavies axis of rainfall is expected to set up, so added a TEMPO to account for this potential between 13-17z. Once the rain shield begins to depart to our east towards the end of the period, light showers will linger through the end of the TAF period with primarily MVFR conditions remaining steady. Winds throughout the period will be light, under 10 kt sustained, and prevailing largely out of the northeast.

Outlook...

Sunday Night: Moderate Operational Impact. Chance of SHRA. Monday: Low Operational Impact. Breezy. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: Low Operational Impact. Slight Chance of SHRA. Thursday: Moderate Operational Impact. Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.